Double impeller impact breaker



Oct. 3, 1967 N. H. KESSLER ETAL 3,344,999

DOUBLE IMPELLER IMPACT BREAKER Filed Oct. 19, 1964 '2 Sheets-Sheet 1 FIGFIG 2 INVENTORS NORMAN H KESSLER A. LILLIG BY 4 f 7 ATTORNEY Oct. 3,1967 Filed Oct. 19. 1964 N.H.K ESSL.ER ETAL DOUBLE IMPELLER IMPACTBREAKER 2 SheetsSheet 2 INVENTORS NORMAN H. KESSLER FLOYD LILLIG BY 44%{ii 1N4;

ATTORNEY United States Patent ()fiice 3,344,999 DOUBLE IMPELLER IMPACTBREAKER Norman H. Kessler and Floyd A. Lillig, Cedar Rapids,

Iowa, assignors to Norman H. Kessler, Cedar Rapids,

Iowa, and Harriet F. Derrick, Chula Vista, Calili,

tenants in common Filed Oct. 19, 1964, Ser. No. 404,755 3 Claims. (Cl.241-154) ABSTRACT OF THE DISCLOSURE A double impeller impact breakeremploying, in its preferred form, a pair of impellers having equalhammer circles, both impellers being driven in the same direction and atthe same speed, the primary impeller initially receiving the material tobe crushed having fewer hammers than the secondary impeller and a speedof rotation effective to permit material to enter its hammer circle andbe eflectively crushed, the material thereafter being propelledtherefrom toward the secondary impeller at a velocity sufiicient topenetrate the hammer circle of the latter.

Crushing apparatus of the double impeller impact type is well known tothose skilled in that art where rocks, ores and similar hard materialsare broken into smaller pieces of a desired size for a particular use.These double impeller impact breakers produce what is commonly referredto as dual impact action in which two impellers cooperate withstationary breaker bars to break up the material fed to the machine. Theraw material is fed into the rotating impellers which carry a pluralityof impeller bars or hammers that break up the rock by impact and alsoforcibly direct the material against the stationary breaker bars wherethe impact produces further disintegration of the material.

In some machines of this type, the two impellers rotate in oppositedirections so that material fed between them is forcibly ejectedupwardly and outwardly against stationary breaker bars located to eachside of the impellers. Other machines of this type employ the principlein which both impellers rotate in the same direction, the material beingdirected into the path of the first impeller which produces initialbreakage and directs the material forcibly against a single gratestructure located adjacent the second impeller where only the materialof finished size is immediately discharged. The remain-ing oversizedparti cles are deflected by the grate structure and directed into thepath of the second rotating impeller where the material is furtherbroken up.

In this second type of impact breaker, in which the impellers rotate inthe same direction, most of the break ing is accomplished by impact withthe rotating impellers. However, because of the low feed height which iscommonly used on these machines, and because all the material isinitially fed to the first or primary impeller, the latter receivesconsiderably more wear than the more remote or secondary impeller. Thisis because the material does not attain suflicient velocity to penetratethe hammer circle of the primary impeller to any great extent andtherefore the material scuffs oflf the ends of the hammers or barscausing excessive wear. This problem can be corrected in part by slowingdown the primary impeller thereby producing a greater time intervalbetween the 3,344,999 Patented Oct. 3, 1957 hammers on the primaryimpeller and thus greater opportunity for penetration of the materialinto the hammer circle. However, by slowing down the speed of theprimary impeller, the peripheral velocity of the hammers is also reducedwith a result that the material is not struck with sufficient impact todo an efficient breaking job. The inadequately broken, oversizeparticles of material are then transferred over to the secondaryimpeller which must then accomplish most of the work, and as a resultits hammers will wear excessively. Slowing down the primary impelleralso reduces the elficiency and capacity of the machine.

- Summary of the invention It is therefore the chief object of ourinvention to provide an improved impact breaking apparatus of the doubleimpeller type in which both impellers rotate in the same direction.According to the principles of our invention, we provide an impactbreaking apparatus in which the secondary impeller contains a greaternumber of hammers than the primary impeller thus providing for a greatertime interval between the hammers of the primary impeller even though itmay be rotating at substantially the same speed as the secondaryimpeller. With this ar rangement, the hammers on the primary impellerhave the same peripheral velocity and produce an impact equivalent tothat of the secondary impeller. A machine constructed according to theprinciples of our invention, in which, for example, the primary impellerhas fewer hammers but is rotated at the same speed as the secondaryimpeller, thus produces material at substantially the same capacity asprior art machines of this type. However, the work load, as well as thepower requirements for each impeller, is more evenly distributed betweenthe two impellers, the increased breakage achieved by the primaryimpeller augmenting its hammer life.

These and other objects and features of our invention will be morereadily apparent from -a consideration of the following detaileddescription of the preferred form thereof.

Brief description 0] the drawing FIGURE 1 is an elevational side view ofa crushing apparatus constructed according to the principles of ourinvention and shown with the side panel removed to disclose interiordetails;

FIGURE 2 is a side elevational view of the other side of the crushingapparatus; and

FIGURE 3 is an end elevational view of the crushing apparatus, the viewbeing of the feed end of the machine.

Description of the preferred embodiment Referring now to the drawings,the crushing apparatus comprises a generally rectangular enclosureconsisting of a front or feed end wall 10 and a rear end wall 1'2 joinedby two side walls 14 and 16 and a top wall 18. The

crushing unit shown can be adapted for installation in any mon feedingress or mouth 21 which is covered by a plurality of depending chains22 and 24, respectively. Cha ns 22 and 24 permit the material to be fedinto the crushing unit while minimizing the possibility of some of thematerial being thrown out of the unit through feed ingress 21. Thematerial can be fed into feed ingress 21 in any suitable manner, such asby a feeder of known type (not shown), and the incoming material isguided into the path of the impellers by an adjustable feed plate 26.

Inside the crushing unit are rotatably mounted a primary impeller 28 anda secondary impeller 30. These impellers are mounted for rotation aboutparallel, horizontally disposed shafts 32 and 34, respectively, whichturn in suitable bearings 33 carried outside side Walls 14 and 16. Theends of shafts 32 and 34 are extended a suflicient distance beyond sidewall 14 to receive drive sheaves 36 and 38, respectively, which aredriven by belts or other suitable means from a power source (not shown).As shown in FIGURE 1, the primary impeller 28 is located near the feedend of the machine beneath the adjustable feed plate 26, the angle ofwhich can be adjusted so that the incoming rock is guided into the pathof the primary impeller 28. The primary impeller 28 carries twodiametrically opposed, reversible hammers 40 which are locked in placewith wedge blocks 42. The secondary impeller 30 carries three equallyspaced hammers 44 also held in place on impeller 30 by suitable wedgeblocks 46. The primary impeller 28 and secondary impeller 30 are drivenpreferably at the same peripheral speed and in the same direction, asindicated by the arrows in FIGURE 1, such as to propel the materialtoward the rear end wall 12. The hammer circles, of the impellers 28 and30, which are the circles described by the outer edges of the hammers onthe impellers, are preferably closely adjacent each other.

As the incoming rock is fed into the crushing unit and guided into thepath of the primary impeller 28, the material penetrates the hammercircle and is intercepted by the hammers 40, being broken up by theimpact and simultaneously projected upward and to the rear of thecrushing unit. A series of spaced, horizontally disposed breaker bars 48are mounted within the enclosure of the crushing unit along the top andupper rear portion thereof ahead of rear wall 12. Most of the materialwhich has been reduced by impact with the primary impeller 28 to afinished size, passes down by impeller 30- and is discharged from thecrusher. Particles of material which are oversized are broken up againstbreaker bars 48 and deflected therefrom back downwardly into the path ofthe secondary impeller 30 where they are broken by further impact of thehammers 44. Preferably, breaker bars 48 function primarily to furtherbreak up oversize material. Alternately, breaker bars 48 may be of aform and arrangement which function primarily to permit only apredetermined maximum size of material to pass therethrough and bedischarged from the crusher. In any event, the process is repeated untilthe material is small enough to pass down by impeller 30 (and/or throughbreaker bars 48 in the alternate arrangement just referred to). Astripper bar 50, mounted below the lowermost breaker bar 48 adjacent thehammer circle of secondary impeller 30, regulates the maximum size ofmaterial permitted to pass down by impeller 30. The mounting 52 for thestripper bar 50 is of any suitable design that permits its proximity tothe hammer circle of the secondary impeller 30 to be changed, the use ofshims 54 being shown in the drawings for this purpose. Additionaldetails of the construction and functioning of the machine are wellknown to those skilled in the art, the machine being basically a doubleimpeller impact breaker with the exception of the rotor construction andoperation.

Accordingly, in order to balance the wear on the hammers and the amountof work done by each impeller, we have provided a primary impeller whichhas fewer hammers than the secondary impeller. If, as is preferred,

both impellers have hammer circles of equal diameter and are rotated atthe same speed so that the peripheral speed of each is sufiicient forefficient reduction of the material, the intervals between hammers onthe primary impeller will be greater than the intervals between thehammers on the secondary impeller. Hence, increased penetration of therock into the hammer circle of the primary impeller has been providedwithout decrease of the peripheral velocity of the hammers on theprimary impeller below that necessary for efiicient crushing. Thus, ourinvention, as embodied in the particular application thereof justdescribed, substantially equalizes the wear and work load on eachimpeller, resulting in more efiicient breakage of the material as wellas lengthening the overall life of the hammers.

It will be understood by those skilled in the art that the objects ofour invention can be accomplished using various combinations ofdifferent numbers of hammers on the primary and secondary impellers aswell as different impeller speeds. The important thing is that theprimary impeller have fewer hammers than the secondary impeller and aspeed of rotation sufficient to efficiently crush the incoming materialand project it therefrom at a velocity greater than that with which itentered the hammer circle of the primary impeller. The secondaryimpeller can carry a larger number of hammers than the primary impellerwithout impairment of its crushing ability even though rotating at thesame speed than the primary impeller because the material enters thehammer circle of the secondary impeller at a higher velocity than itenters the hammer circle of the primary impeller. Furthermore, it is notnecessary that both impellers have the same peripheral speed inasmuch asdifferent speeds of each may be accommodated by varying the number ofhammers on each. The essential thing is that the combination of thenumber of hammers on each impeller and their peripheral speeds affordefiicient and substantially equal service by each impeller.

Accordingly, the foregoing preferred form of the invention has beenshown for purposes of illustration only and it will be apparent to thoseskilled in the art that various other revisions and modifications can bemade in the specific construction of the illustrated embodiment withoutdeparting from the spirit and scope of the invention. Thus it is ourintention that any such revisions and modifications be included in thescope of the following claims.

We claim:

1. In an impact breaker of the double impeller type having an enclosureprovided with an upper material feed inlet and a lower materialdischarge outlet, a primary impeller rotatable about a horizontal axisin said enclosure and having a primary hammer circle, said primaryimpeller being disposed below said feed inlet effective to permitmaterial introduced therethrough to gravitate to said primary hammercircle, a secondary impeller rotable about a horizontal axis in saidenclosure and having a secondary hammer circle, the axis of saidsecondary impeller being laterally spaced from the axis of said primaryimpeller so that said hammer circles thereof lie closely adjacent eachother, stationary breaker means disposed in said enclosure and spacedabove said secondary hammer circle and to the side thereof remote fromsaid primary hammer circle, and driving means for rotating each of saidimpellers at selected speeds, the direction of rotation of each of saidimpellers being identical and such that material entering said feedinlet is projected by said primary impeller toward said secondaryimpeller and by both of said impellers toward said breaker means, theimprovement comprising: one or more impact hammers mounted on andextending from the periphery of said primary impeller and describingsaid primary hammer circle, and two or more impact hammers mounted onand extending from the periphery of said secondary impeller anddescribing said secondary hammer circle,

the number and spacing of said hammers on each of said impellers and theselected speed of rotation thereof in relation to the diameters of theirhammer circles all being such relative to each other that materialgravitating from said feed inlet may enter the hammer circle of saidprimary impeller and the material projected from said primary impellermay enter the hammer circle of said secondary impeller and beeffectively crushed by the hammers of both of said impellers, the numberof hammers on said primary impeller being less than the number ofhammers on said secondary impeller.

2. The device of claim 1 wherein the diameters of the hammer circles ofsaid impellers are substantially equal and said impellers are driven atsubstantially the same speed.

3. The device of claim 2 wherein said primary impeller is provided withtwo equally spaced impact hammers and said secondary impeller isprovided with three equally spaced impact hammers.

References Cited UNITED STATES PATENTS 675,751 6/1901 Moustier 241--154X 2,618,438 11/1952 Chrystal 241-154 X 2,767,928 10/1956 Hanse et a1.241154 X 2,862,669 12/1958 Rollins 241154 FOREIGN PATENTS 706,552 5/1941Germany.

ANDREW R. JUHASZ, Primary Examiner.

1. IN AN IMPACT BREAKER OF THE DOUBLE IMPELLER TYPE HAVING AN ENCLOSUREPROVIDED WITH AN UPPER MATERIAL FEED INLET AND A LOWER MATERIALDISCHARGE OUTLET, A PRIMARY IMPELLER ROTATABLE ABOUT A HORIZONTAL AXISIN SAID ENCLOSURE AND HAVING A PRIMARY HAMMER CIRCLE, SAID PRIMARYIMPELLER BEING DISPOSED BELOW SAID FEED INLET EFFECTIVE TO PERMITMATERIAL INTRODUCED THERETHROUGH TO GRAVITATE TO SAID PRIMARY HAMMERCIRCLE, A SECONDARY IMPELLER ROTATABLE ABOUT A HORIZONTAL AXIS IN SAIDENCLOSURE AND HAVING A SECONDARY HAMMER CIRCLE, THE AXIS OF SAIDSECONDARY IMPELLER BEING LATERALLY SPACED FROM THE AXIS OF SAID PRIMARYIMPELLER SO THAT SAID HAMMER CIRCLES THEREOF LIE CLOSELY ADJACENT EACHOTHER, STATIONARY BREAKER MEANS DISPOSED IN SAID ENCLOSURE AND SPACEDABOVE SAID SECONDARY HAMMER CIRCLE AND TO THE SIDE THEREOF REMOTE FROMSAID PRIMARY HAMMER CIRCLE, AND DRIVING MEANS FOR ROTATING EACH OF SAIDIMPELLERS AT SELECTED SPEEDS, THE DIRECTION OF ROTATION OF EACH OF SAIDIMPELLERS BEING IDENTICAL AND SUCH THAT MATERIAL ENTERING SAID FEEDINLET IS PROJECTED BY SAID PRIMARY IMPELLERS TOWARD SAID SECONDARYIMPELLER AND BY BOTH OF SAID IMPELLERS TOWARD SAID BREAKER MEANS, THEIMPROVEMENT COMPRISING: ONE OR MORE IMPACT HAMMERS MOUNTED ON ANDEXTENDING FROM THE PERIPHERY OF SAID PRIMARY IMPELLER AND DESCRIBINGSAID PRIMARY HAMMER CIRCLE, AND TWO OR MORE IMPACT HAMMERS MOUNTED ONAND EXTENDING FROM THE PERIPHERY OF SAID SECONDARY IMPELLER ANDDESCRIBING SAID SECONDARY HAMMER CIRCLE, THE NUMBER AND SPACING OF SAIDHAMMERS ON EACH OF SAID IMPELLERS AND THE SELECTED SPEED OF ROTATIONTHEREOF IN RELATION TO THE DIAMETERS OF THEIR HAMMER CIRCLES ALL BEINGSUCH RELATIVE TO EACH OTHER THAT MATERIAL GRAVITATING FROM SAID FEEDINLET MAY ENTER THE HAMMER CIRCLE OF SAID PRIMARY IMPELLER AND THEMATERIAL PROJECTED FROM SAID PRIMARY IMPELLER MAY ENTER THE HAMMERCIRCLE OF SAID SECONDARY IMPELLER AND BE EFFECTIVELY CRUSHED BY THEHAMMERS OF BOTH OF SAID IMPELLERS, THE NUMBER OF HAMMERS ON SAID PRIMARYIMPELLER BEING LESS THAN THE NUMBER OF HAMMERS ON SAID SECONDARYIMPELLER.